Materials having a lower voltage range than lithium have been used for an anode of a lithium secondary cell. Accordingly, a potential change inside an electrode may be often unbalanced, for example, when a graphite-based material having a low potential is used as the conductive material, the potential to lithium is frequently moved to near 0 V. At this time, lithium may be precipitated on the surface of graphite, and as a result, the performance of the cell may be deteriorated.
The all solid cell has the high content of the conductive material due to a complex electrode structure in which an anode active material, a solid electrolyte, and a conductive material are mixed together. The nonuniformity of voltages often occurs due to the heterogeneous mixing of the electrodes compared to a liquid-based cell constituted by only the active material and the conductive material. In addition, since the conductive material directly contacts the solid electrolyte containing a lot of lithium ions, lithium may be precipitated on the surface of the conductive material having a potential close to 0 V. The precipitated lithium may cause an interfacial reaction with the solid electrolyte to degenerate the solid electrolyte or deteriorate the performance of the cell through dendrite growth.
In the related art, a configuration in which a conductive material and a coating layer are formed on the surface of an electrode active material has been disclosed, however, the process may be complicated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.